In hybrid vehicles, the energy density of the energy storage unit is of secondary importance; compromises in energy density have been made to reach the high power density of pulse batteries.For example, nickel metal hydride batteries designed for EVs have an energy density of 70Wh/kg and a power density of 250 W/kg, while those designed for hybrid vehicles have an energy density of 40–45Wh/kg and a peak power density of 600–700W/kg.Such a hybrid vehicle would not function as a ZEV in urban/freeway driving unless the driver was willing to accept reduced acceleration performance.Tags: Fashion Photography Dissertation ProposalDulce Et Decorum Est Critical Essay NotesEssay Essential QuestionsKey Analysis On Subhiksha Failure EssayEssay About Using Computers Saves A Lot Of TimeIbo Extended Essay SupervisorEssays On Realism In LiteratureComparison Essay Lord Of FliesCollege Essay ConsultantsMy Favorite Place Essay Introduction
This means that in packaging the hybrid driveline, the electrical drive components take up only a fraction of the space available and finding room for the mechanical components, such as the engine, transmission or torque coupler, can present a difficult challenge.
The key component in the hybrid driveline that permits it to operate more efficiently than the engine/transmission in a conventional car is the electrical energy storage unit.
In the parallel hybrid, the mechanical output of the engine can be used to both power the vehicle directly and to recharge the battery or other storage devices using the motor as a generator.
In recent years, a third type of hybrid configuration, the dual mode, is being developed that combines the series and hybrid configurations.
The engine would be used only on those days when the vehicle is driven long distances.
Hybrid vehicles designed to maximize fuel economy in an all-purpose vehicle could use the series, parallel, or dual configurations depending on the characteristics of the engine to be used and acceptable complexity of the driveline and its control.
There are a large number of ways an electric motor, engine, generator, transmission, battery, and other energy storage devices can be arranged to make up a hybrid-electric driveline.
Most of them fall into one of two configurations—series and parallel.
A range-extended electric vehicle would most likely use the series configuration if the design is intended to minimize annual urban emissions.
It would be designed for full-performance on the electric drive alone.